Firearm



l. LEWIS.

FIREARM.

APPLICATION man Nov. 2a. 191s.

Patented Oct. 3, 1922.

l. N. LEWIS.

FIREARM.

APPLICATION FILED NOV. 23, |918.

Patented Oat. 3, 1922.

I. N. LEWIS.

FIREARM. APPLlcATIoN FILED Nov, 23, |918.

Patented Oct. 3, 1922.

4 SHEETS-SHEET 3.

l. N. LEWIS.

FIREARM.

APPLICATION FILED Nov. 23. 1918.

Patented oet. 3, 1922.

4 SHEETS-SHEET 4.

@mum/Ton laac N- Lema.

@m I Nm I www@ 5y Mh Hrlformzy.

Patented Oct. 3, 1922.

UNITED STES TENT FIREARM.

Application filed November 23, 1918. Serial No. 263,824.

I To all whom t may concern:

Be it known that I, IsAAo NEWTON LEWIS, a citizen of the United States of America, residing at l Russell Terrace, Montclair, in the county of Essex and State of New. Jersey, have invented certain new and useful Improvements in Firearms, of which the following is a specification.

This invention relates to firearms, and particularly to automatic or semi-automatic firearms in which the gases of discharge resulting fromvthe firing of a powder charge are employed for the purpose of causing operation of the actuating mechanism of the firearm.

The primary object of the present invention is to provide an automatic or semi-automatic firearm of extremely simple and light construction and arrangement, involving a minimum number of parts, and which shall be capable of more rapid, efcient and cleaner operation than gas operated firearms as now in use. Another object of the invention is to provide an automatic or semi-automatic firearm constructed andarranged to be 'operated in accordance with the method of operation described and claimed in my co-pending application No. 263823 filed November 23rd 1918. Other objects" are to provide an improved form of firearm in which the rases of discharge are utilized to effect an air cooling of the barrel, and if desired, of the actuating mechanism of the firearm and to provide a firearm in which the gases of discharge are utilized in an improved manner to reduce or neutralize the recoil of the firearmv following the explosion of the powder charge.

The invention primarily consists in an automatic or semi-automatic firearm in which means are provided for influencing the gases of discharge resulting from the firing of a powder charge to produce a shock or very rapid pressure impulse, together with means for transmitting said shock or impulse to the actuating mechanism of the firearm to operate the same.

The shocks or pressure impulses may be produced by providing means for checking or retarding the forward movement of the discharge gases., Such forward movement of the gases is extremely rapid, and the sudden shock or rapid pressure impulse is produced when themovement is momentarily checked or retarded by the contact of the gases with said means. The shocks or impulses may also be 'produced by providing means for checking or retarding the free expanslon of the discharge gases issuing from the muzzle end of the gun barrel.

I An important distinction must be drawnat the outsetV between the present automatic or semi-automatic firearm operated by shocks or pressure impulses, and firearms operated by the direct pressure of the heated gases of discharge upon parts connected with the actuating mechanism of the firearm. In the improved firearm the hot gases of discharge do not necessarily come into direct contact with the actuating mechanism or parts connected thereto to transmit the shocks or impulses, as such shocks or impulses-may be, and Vpreferably are transmitted to said mechanism, or said parts, through the medium of an intervening column of air. Thus said mechanism, or said parts, do not become highly heated by the gases and do not become fouled by deposits therefrom, enabling the firearm to be operated for more extended periods without cleaning, and preventing jamming or inefficient operation due to said fouling deposits., Furthermore, as the shock or impulse is produced and transmitted to the actuating mechanism practically instantaneously with the discharge of the bullet from the barrel, the speed of operation is increased when firing entirely automatically, and a greater number of bullets may be discharged in any given interval.

The invention also consists in an automatic or semi-automatic firearm in which means are provided for infiuencing the gases of discharge resulting from the firing of a powder charge to produce a shock or very rapid pressure impulse, together with means operated by said shock or impulse to effect a circulation'of cooling air over or around the barrel, and if desired, over the actuating mechanism of the gun.

The invention further consists in an automatic or semi-automatic firearm, in which means are provided for influencing the gases of discharge resulting from the firing of a powder charge to produce a shock or very rapid pressure impulse of such a nature as to reduce or neutralize the recoil of the firearm due to the explosion of the powder charge;

Still further features of the invention relate to improved constructions and arrangements of the actuatingrmechanism, trigger 'or when advancing under fire.

lmechanism and cartridge magazine of the l purpose of illustration only, and without any intention of limiting the invention to any particular construction or type of firearm, is shown a machine or rapid lire gun Yadapted to be operated automatically or semi-automatically in accordance with theY principles of the present invention.

In these drawings Figure 1 is a side elevational view of one form of machine or rapid fire gun constructed in accordance with the principles of the present invention;

Figure 2 is a longitudinal sectional view of the body or receiver of the gun and parts carried by 'or working within the saine, the

operating parts being shown in substantially the rearmost positions to which they are moved by the shock-operated means;

Figure 3 is a det-ail viewof the body or receiver, with the parts in position ready to move into firing position when thel trigger mechanism is actuated;

Figure 4 is a similar view but showing the operating parts in the positions they occupy at the instant of firing;

Figure 5 is a longitudinal sectional View of the forward portion of the gun showing one form of means for producing the shocks or rapid pressure impulses, and means for transmitting the shocks or impulse to the actuating mechanism of the gun, the latter .means being shown in position corresponding to that of the parts in Figure 4;

Figure 6 is a cross-sectional view through the butt-tang, looking toward the muzzle of the gun and showing the rear sight;

Figure 7 is a view of the butt-tang looking toward the rear;

Figure 8 is a sectional detail plan view of the butt-tang and rear sight;

Figure 9 is an end Viewof the body or receiver, looking toward the muzzle of the gun, with the butt-tang removed;

Figures 10,11, Vl2, 13, 14, 15, 16, and'17 are cross-sectional views of the gun, taken respectively on the lines 10-10, 114-11,

12-12, 13-13 and 14-14 of Figure 2, and

the lines 15-15, 16-16 and 17 -17 of Figure 5 Y A Figurel is a detail sideelevational view of part of the body and trigger mechanism, Ilooking at the Side of the gun opposite to that vshown in Figures 2, 3 and 4;

I tions when the trigger is pressed;

Figures 25 and 26 are detail plan views, partly in section, of the trigger mechanism, the operative parts being shown respectively in the positions corresponding with igures 22 and 23;

Figure 27 is a detail plan view of the breech block or bolt; l

Figure 28 is an elevational view of the forward end of the bolt;

Figure 29 is a sectional vie taken on .the line 29-29 of Figure '27, and showing the 90 extractor member carried by the bolt;

Figure 30 is a longitudinal sectional view of the body of the gun taken approximately onvthe line 30-30 of Figure 12, and showing the ejector mechanismI .in the act of ejecting an empty shell;

Figure 31 is an outside elevational view of -tlie cartridge magazine Figure 32 is'a plan view of said magazii e;

Figure 33 is a sectional plan view of lie 100 magazine showing the arrangement of the cartridges therein; and

Figure 34 is a detail perspective view of the spring-actuated follower of the magazine. l In one form the means for utilizing the gases of discharge .to produce the shock comprise a chamber and a piston member movable within the said chamber, the movement of the piston member 'being transmitted to 110 i the actuating mechanism of the firearm. The said chamber is formed betvsgen the gun barreland al casing surrounding the latter ong its entire length and extending forward in front of the muzzle end thereofrll At its forward end the wall of the casing is turned inwards forming an inwardly p rojecting flange having a central aperture or lmouth of slightly greater diameter than that nism of the gun. When the rear end of the bullet has left the mouth of the casing the confined gases in the chamber and inside the gun barrel -can issue freely through the mouth of the casing. The gases still at high pressure within the gun barrel issue from the muzzle thereof and expand with great turbulence within the chamber simultaneously with the escape of gases through the mouth of the casing. During the initial part of this period the pressure wave transmitted rearwardly inside'the chamber to the piston member is increasing in intensity and finally reaches a maximum. The maximum pressure on the piston is succeeded Vby a fall of pressure, the gases issuing from the mouth of the casing with sufficient kinetic energy to induce a partial vacuum within the chamber and gun barrel. Meantime the piston member is still moving rearwards and may be made to uncover a passage formed by' an enlargement of the diameter of the wall of the casing. A free passage is then provided inside the casing from the rear end thereof to its mouth. Fresh cold air enters the chainber through inlet ports near the rear end of the casing, and a powerful draught is induced by the kinetic energy of the gases still issuing from the mouth of the casing.

The pressure and kinetic energy trans'- mitted to the piston member is employed partly in effecting the backward stroke of the actuating mechanism and partly in energizing a return spring which is caused to effect the forward or return stroke of the actuating mechanism.

It is to be particularly observed that the velocity of the gases issuing from the mouth of the casing is that due to the head or pressure within that portion of the chamber between the muzzle end of the barrel and the mouth of the casing. This pressure varies rapidly but its maximuml and average values are much less than the corresponding values impinge upon the shock producing obstruction in their path partially neutralize and materially lessen the free recoil of the arm.

Referring more in detail to the drawings, and particularly to Figures 2, 3, 4 and 5 thereof, it will-abe noted -that thegun barrel .1 at its rear or breech end has a screw@ threadedconnection at 2 with the forward or in the case ofdischarge gases issuing frombreech end of the body or receiver 3. Surrounding the barrel 1 throughout its entire length is a casing 4 which at its rear end is mounted upon the forward end of the body 3, being shaped to properly fit upon said forward end as will appear from Figure 14, and being securely connected thereto by any suitable means. The particular means shown comprises a band 5 which is split at its lower part, as shown clearly in Figures 2 and 13, and has its two ends provided with screw-threads 6 and conical surfaces 7, which are arranged to co-.act with similar screwthreads and conical surfaces on the interior of a nut 8, the exterior surface of which may be knurled or roughened in any suitable manner. Tile edges of the band 5 are inwardly flanged at 9 to co-act with the outwardly projecting flanges 10 formed on the forward end of the body 3, and the rear end of the casing 4, so that by applying the band over the ends of the body and casing and tightening the nut 8 on the threads 6, the halves of the band are caused to /tightly grip the 'body and casing, and the fianged edges 9 co-act with the flanges 10 to securely hold the casing on the body, with its rear surface abutting against a shoulder on the latter, as clearly shownvin Figures 2 and 4.

The forward portion of the casing 4 is supported by means of a spider support 11, Figures 5 and 17, consisting of a cylindrical sleeve fitting onto the cylindrical portion 12 at the muzzle end of the barrel 1, and provided with radially extending arms or fins 13 which engage at their outer edges with the interior of the casing 4. To afford additional support to the casing, some or all of the arms 13 may extend rearwardly7 be- 105 yond the rear end of the sleeve 11, with their outer edges engaging the interior of the casing, as shown in Figure 5.

. The forward portion 14 of the casing 4 is reduced in size, so that it is concentric. 110 with the gun barrel 1, the casing being of larger diameter than the barrel so that an annular space 15 is formed between them, which will be referred to later. The portion of the casing 4 to the rear of the shoulder 115 16 is of the cross-section illustrated in Figures 14 and 15.

The extreme forward end 17 of the casing extends some' distance beyond the forward or muzzle end of the gun, as shown 120 in Figure 5, and constitutes one form of means for producing the shocks or pressure impulses which are utilized to effect operation of the actuating mechanism of the firearm. This forward end 17 may be formed in 125 various ways in order to produce the shocks or pressure impulses. Thus, as illustrated in Figure 5, the casing wall at its forward end is turned inwardly as shown at 18 to produce an inwardly extending flange forming in 130 effect an apertured forward wall on the casling, which permits the passageof the bullet and the subsequent retarded, escape ofthe gases of discharge. As the gases of discharge owing freely from the muzzle end of the barrel, following the discharge of the bullet therefrom, come into contact with the. apertured forward wall 18 of the said casing or chamber, the consequent momentary check or retardation of the gases causes the production of the aforesaid shock or backward pressure impulse, and this shock or impulse mayv be transmitted backwardly to the actuating. mechanism by suitable means, as hereinafter referred to. By regulating the size of the aperture'in the forward wall 18 of the casing 4, or the distance of said wall from the muzzleend of the gun barrel 1, or by suitably proportioning the size of the aperture and the distance between the wall and muzzle end of the gun barrel, a pressure impulse or shock may be produced of such energy as to effect operation of the actuating mechanism in the most satisfactory and efficient manner. The regulation of the size' of the aperture and its distance from the end ofI the barrel permits the energy of the shock or impulse to be determined with eXtreme, accuracy, whereby the actuating mechanism may be operated with great nicety and smoothness and without imparting unnecessary shocks to the same or otherwise straining the parts of the gun.

The forward portion )17 of thel casing 4 terminating in' thefapertured end wall 18,

may be of cylindrical form, so that the shockr or impulse is produced entirelyby the contact of the rapidly moving gases with the said apertured wall, or as shown in Figure 5, said portion may be of slightly conical or tapered form, the conical or'tapering wall of said portion co-operating with the apertured end wall, in producing the shock or impulse.

lternatively the checking or retarding of the gases of discharge may be effected entirely by tapering the wall of the .forward portlon of the casing 4, the extreme'forward end of the casing being open, and the forward movement of the gases being checked or retarded due to the passage of said gases through the chamber of gradually reducing cross-section formed by the taperlng wall of the casing. It will be clear thatin this case also, by regulating the size of the aperture at the 'forward end of the casing or by regulating the distance of said aperture from the muzzle end of the barrel, or by suitably proportioning the size of the aperture and the distance of the same from said muzzle, the energy of the shock or impulse -produced may -be accurately controlled. Further, the checking or retarding-of the gases might be effected by the use of a forward caslng portion of cylindrical form having its extreme forward end open by so determining the internal diameter ofsaid portion that the free expansion of the gases of discharge from the muzzle end of the gun barrel into the cham'- ber formed by said casing portion is momentarily checked as the bullet is discharged.

The shocksn or impulses produced by the regulation of the discharge gases in the man-4 ner above described, or in any other suitable manner, may be transmitted to the actuating mechanism of the firearm by any suitable means. For example, they may be transmitted through the medium of a piston work- 'ing in a suitable cylinder and connected by a rod or other convenient means to the bolt or other part of the actuating mechanism. 'In the particular construction illustrated in Figure 5, a piston 19 of annular form is ar` ranged to reciprocate within the annular space 15 between the casing portion 14 and the gun barrel. The forward end or head of the piston 19 is bored to ft upon a cylindrical portion 2O of the gun barrel, and at its outer periphery said head fits the interior surface of the concentric portion 14 of the casing. yThe head of the piston may be grooved as at 21 to prevent leakage, or may be otherwise packed. At its rear end the piston 19 is provided with a radial extension 22, Figures 5 and 15, to which is connected, as by means of screw-threads, although it may be integral thlerewith, if desired, the forward end of a piston or connecting rod 23. Thisrod eX- tends rearwardly into the body or receiver 3 and is therein connected 4to an operating member 24, hereinafter referred to. The radial extension 22 and rod 23 are arranged to reciprocate within the enlarged portion of the casing 4 to the rear of the shoulder 16,the rod being guided in the forward end of the body 3, and preferably being of tubular form to reduce the weight while retaining the necessary strength.

It will be noticed that the annular space 15 in front of the piston 19 is in free com` munication with the chamber formed by the forward end 17 of the casing 4, so that a column of air is always maintained in fro'nt `of the piston. On the firing o'f a cartridge or powder charge, the sudden shock or rapid pressure impulse produced by vthe retarding or checking of thegdischarge gasesin the manner abovedescribed, is transmitted to.

the column of air in front of the piston 19 and by said column to the piston itself, the latter being thereby moved rearwardly so as to actuate the operating member 24. The

spider Support 11 as will be seen from Figure 17, permits the free communication between thev space 15 and the chamber` within the casing portion 17, while affordingthe necessary support for vthe casing.

The actuatin mechanism of the firearm is located withint e body or receiver 3, .and the particular arrangement of such mechanism illustrated, but to the use of which the invention is not in any way restricted, comprises essentially the cylindrical operating member 24 to which the rod 23 is' connected, the hollow cylindrical breech block or bolt 25, and the firing pin 26 slidably arranged within said block or bolt, as will be clear from Figures 2, 3, 4, 9 and 10. The body 3 of the gun is formed with two longitudinal parallel bores 27 and 28, Figures 2 and 9 to l2, which are connected throughout practically their entire length by the slot 29. The operating member 24 is guided in the upper bore 27 and the breech block or bolt 25 is guided in the lower bore 28. The operating member is provided with a post 30 which extends downwardly through the slot 29 of the body into L,the cam slot 3l formed in the upper surface of the bolt 25, said post having a. reduced portion which enters a slot in the firing pin 26, as will be clear from F igures 2 and 10. The return spring 32 sur` rounds a rearward extension on the operating member 24, bearing against said member at its forward end, and at its rear end against the plate 33 of the butt-tang 34.

The cam'slot- 31 of the bolt 25, see Figure 27, comprises rearand forward portions connected by inclined cam surfaces 35 and 36, with which the post 30 is adapted to engage during the forward and return movements of the operating member 24. The bolt 25 is provided at its upper part with a projection' 37 which normally extends into the slot 29 and thereby prevents rotation of the bolt, but which when ythe bolt is in its extreme forward position coacts with a short circumferential slot 38 in the wall of the lower bore 28, indicated in dotted lines in Figure 12, and permits the bolt to be rotated, first in one direction and then in the other, by the engagement of the post 30 with` the cam surfaces 35 and 36. The forward end 39 of the bolt is reduced in diameter and is provided with four angula-rly spaced locking or resistance lugs 40 which areadapted tocoact with four angular-ly spaced locking lugs 41 extending inwardly from the wallof the lower bore 28 at the forward end thereof, as clearly shown in Figures 2 and 12. The firing pin 26 in the form illustrated is double ended, that is, it is provided with two 'oppositely extending firing projections 42, so that in the event of breakage of one proj ection the firing pin may be simply reversed to bring the other projection into operative position. 0bviously, however, a single firing pin may be employed, or the post 30 might be provided or formed with a ring projection. The firing pin 26 is slidably mounted within the bore of the lbolt 25, the forward wall of the bolt being bored to substantially correspond with the firing projection 42, so that the extreme forward end of the latter will when the pin is in firing position extend beyond the forward face of the bolt, to lire vthe cartridge, in the usual manner.

When the parts of the actuating mechanism are in the .positions illustrated in Figure 3, and the bolt 25 is released, as hereinafter described, the return spring 32 moves the operating memiber 24 forwardly, and th'e post 30 being in engagement with the inclined surface 35 of the cam slot 31, the 'bolt 25 moves forwardly with the post and operating memiber,A since said bolt is prevented fromY rotating by the projection 37 engaging the slot 29 in the body. As the parts advance in this relationship, the lowermost lug 40 engages the head of a positioned cartridge 43 and forces the same in advance of the bolt into the chambere/d end of the gun barrel 1, the locking lugs 40 on the bolt passing freely between the locking lugs 41 on the body 3. When the movement of the bolt is stopped by the engagement of the forward end thereof `with the rear or breech end ofthe barrel 1, as shown in Figure 4, the projection 37 coincides with the circumferential slot 38,' in the body, and as the operating member 24 continues `to advance, the post 30 due to its engagement with the inclined surface 35, rotates the bolt, through approximately one-eighth of a revolution, in order to bring the locking lugs 40 in front of the lugs 41 on the body, to prevent rearward movement of the bolt when the cartridge is fired, .the projection 37 moving within the slot 38. The operating member 24 after such rotation moves into the position shown in Figure 4, the post 30 advancing within the forward portion of the cam slot,

and moving the tiring pin 26 into position to strike the head of the cartridge and iire the same. The bolt 25, it will be noted, is securely loclred against rearward movement before the firing pin can advance to fire the cartridge, so that the danger of premature explosion is entirely avoided. The operating member 24, during the described movement thereof, through the medium of the rod 23 connected thereto, moves the piston 19 into its forward position, as indicated in Figure 5.

The discharge gases, following the bullet thus discharged, issue from the muzzle end of the gun into the forward portion of casing 4, and the shock or rapid pressure impulse produced in the manner previously referred to is transmitted through the intervening column of air to the piston 19 and causes the latter to move rearwardly on the portion 20 of the barrel, the rod 23 during such movement forcing the operating member 24 rearwardly. Said member on its initial rearward movement withdraws the firing pin 26. and the post 30 then engages the inclined surface 36 of the cam slot 31, and rotates the bolt 25 in the reverse direction to that of its previous rotation, to bring the lugs 40 into register with the spaces between the lugs 41 and the. projection 37 into register with the slot 29. The post 30 then occupies the rear portion of the cam slot 31, as in Figures 2 and 27, and the bolt 25 is moved by the opgrating member 24 into its rearmost position, against the action of the return spring 32, which is compressed `in order that it may effect a succeeding forward movement of the parts. The rearward movement of the' parts may be li'mited bythe engagement of the rear of the extension on the operating .member with the butt-tang plate 33, such movement being sufficient to ensure that the bolt may be l'atched in its rear position. The shock or rapid pressure impulse produce-d by utilizing the gases of discharge in the manner described is thus transmitted toy the actuating mechanism olf the firearm to energize said mechanism for a succeeding operation thereof. v L' The said actuating mechanism, after operation thereof by the aforesaid shock or pressure impulse, may be restrained from further operation until manipulated bythe user or-operator of the firearm, in which event said actuating mechanism will be manipulable to vcause the firing of individual rounds and will be ra-energized by the shock' or impulse produced at each explosion` of aA cartridge. Or said actuating mechanism may be of such a nature, or so manipulable, that it is not restrained after each discharge of a bullet, in which event any desired numi' ber of cartridges, or the full number of cartridges in the magazine may be successively exploded. With this arrangement the shock or pressure impulse produced by the novel utilization of the gases of discharge of the first cartridge or shell exploded is caused, in the manner described, to energize the actuating mechanism of the firearm so that it will immediately operate to fire the succeedin cartridge or shell operatively positione with respect to said mechanism, the gases of discharge producedat each explosion of a cartridge or shell thereafter energizing the actuating mechanism to fire the succeeding cartridge or shell until the desired number has been fired, or the magazine emptied.

These results may be accomplished by the us of the trigger mechanism illustrated.

in Figures 2, 3,4, 9 to 11,-and 18 to` 26 of the drawings, although other forms ofl trigger mechanism may be advantageously employed and the invention is not restricted to the use of that now to be described. This mechanism comprises a guard or support 44 slidably fitted to the lower part of the body 3, the sidefaces of the guard being provided with longitudinal slots 45, Figures 9 to 11, 21 and 23, adapted to co`actwith longitudinal ribs' or tongues '46 on the in-4 terior of the' lowerpart ofthe body, so that the guard may be slid into place from the rear end of the body, 'they forward end of the guard abutting against a dividing wall 47 on the body, and the rear end of the guard being flush with the rear end of lthe body.

The guard 44 is provided at its upper portion with a recess 48, within which arelocated the sear 49 and the trigger 50 coacting therewith. The sear, is plvotally mounted on a pin 51, and is normally held by a spring 52 with its forward end against va stop 53 extending across said recess and nheld by a spring 57. with its rear end in Contact with the stop 53. The rear end of the trigger is bifurcated at 58, as shown particularly in Figures 19,25 and 26,V to receive the forward reduced end of the sear 49,` and to provide a shoulder 59 adapted to co-act with said end of the sear.

In Figures 2, 3, 4 and 19,/the sear 49 andA trigger 50 are shown in the relative positions which they occupy when the gun is to be fired semi-automatically, lthat is when an individual round is to be fired at'v each pressure of the trigger. With the parts in these relative positions, it will be noticed that when the trigger 50 is pressed its bifurcated rear portion willmove upwardly in the recess 48, and the shoulder 59 will engage underneath the reduced forward end of the sear 49 and will raise said end, lowering the rear end of the sear from the notch 55 in the bolt and thereby releasing ,the latter and permitting it to .be advanced by the return springA 32 acting through the operating member 24 and posit 30 in the manner already described. When the bolt is thus released and moves forward,

the shoulder 59 snaps past the forward end" of the sear, as shown in Figure 4, due to the relative movements of the trlgger and Sear about their respective pivot pins, and thes'ear is returned. toits initial positionready to engage and hold the boltwhen the latter is returned to its rear position by the shock or pressure impulse produced following the discharge. of the bullet. parts in substantially the rearmost positions to which they are moved, the scar 49 having just engaged the notch 55 in the bolt, and

Figure 3 shows the'parts readyto re theY operating member having been advanced slightly relatively to the bolt to engage the post 30 withthe inclined surface 35. The trigger 50, when relieved of. the pressure Figure 2 shows the l thereon, is returned to its initial position by' its spring 57, the elongated aperture 60 perinv resuming its normal position.

y those shown inFigures 2 The trigger and sear are, however, adaptedjto occupy relative positions other than 3 and 4, that is, they may occupy the sa ety p-ositionsindicated in Figures 22I and 25, in'which the trigger may be pressed 'without actuating the Sear, or they may occupy the automatic7 positions indicated in Figures 23, 24 and 26, inwhich whilethe trigger is held pressed, the Sear is retained in inoperative position. j

xBy 'referring to Figures 11, 19, 25 and 26, it will be seen that the trigger 50 is pivotally mounted upon the eccentric central portion 61 of the pivot pin 56, vthis eccentric portion lying within the elongated aperture 60 o f. the trigger.` The pin is provided with an.

enlarged screw-threaded portion 62 threaded into an aperture in the guard 44 to retain the pin in place, 'and with a handle 63 by means of which the pin may be rotated.

When the pin is rotated by means of the handle 63 in a counter-clockwise direction through approximately a quarter revolution,

Vfrom the position shown in Figures 2, 3 and 19 to that shown in Figures 22 and 25, the

trigger is moved slightly forwardly by the eccentric portion 61, so that the shoulder 59 is advanced to bring it just in front of the forward end of the sear and when the trigger is pressed the'shoulder will rise in front of the forward end of the sear without actuating the latter. Thus pressure on the trigger while in this safety position, merely rocks the trigger on its pivot pin and the i i scar is not actuated, neither is the bolt released. When the 'trigger is in this'position the gun ma be carried in entire safety with the bolt he d in the osition shown in Figures 2 and 3 and wit out danger of the firearm being discharged by accidental pressure upon the trigger.

When the pin 56 is rotated by the handle 63 in a clockwise direction through approximatelyia quarter of a revolution, from the position shown in Figures 2, 3 and 19 to that shown in Figures 23, 24 and 26, the eccentric portion 61 of the pin moves rearwardly and permits a slight rearward movement of the trigger so that the shoulder 59 passes farther beneath the front end of the scar, as in Figure 23. Thus-when the trigger is pressed, the shoulder 59 engages the front endaof the sear and actuates the same to release the bolt as previously described, but instead of snapping past theend of the sear, as indicated in Figure 4, .said shoulder remains in engagement therewith so long as the pressure on the trigger is maintained,

and holds the rear end ofthe sear in depressed inoperative position, as indicated in 'Figure 24. The bolt then on its rearward movement is not lheld by the sear, but when4 first cartridge, any desired number thereof within the capacity of the magazine.

The handle 63 is somewhatl resilient or springy and is provided with a notch or groove 6 4 adapted to co-act with the part 65 .of the guard 44 to normally hold the trigger 50 in the semi-automatic position, as in Figure 2. "Whenr the handle is moved into the safety or automatic positions indicated in dotted lines in Figures 25 and 26, it is held in such positions by its resilient frictional pressure against the exterior surface of the guard 44. It is, of course, understood that the pin 56 is so constructed that the slight axial movements thereof. when it is rotated, due to the screw-threads on the portion 62, will not interfere with the movements of the trigger or cause the` parts to jam, suficient play being allowed to permit these movements.

It will be noted that the rod 23 is connected tov the operating member 24 by means of a charging handle 64, the fiat portion of which asses through 'slots in the member and ro and works in a longitudinal slot 65a in the bod 3. By manual rearward operation of this handle 64, the operating member 24, bolt 25 and piston 19 may be moved into the positions shown in Figure 3 ready to lire a cartridge. The flat portion of the handle is rovided with ridges 66, preventing with rawal of the handle" excepting through the enlarged rear portion 67 of the` magazine consists of a casing the side walls .of which are substantially parallel and arranged at such a distance apart that the cartridges 43 placed therein forma double row with the cartridges'in staggered contacting relation as indicated in Figures 12, 32 and 33. The lowermost cartridges rest upon a platform or follower 69 which is pressed upwardly by means of the spring 70 of usual form. The platform69 (see Figures 12 and 34) has-a portion thereof until the trigpressed upwardly at 7l support oneof the -lowermost cartridges in` its'staggered relation to the other thereof, and to en able the upward pressure of. the spring to be positively and vdirectly impartedv to both rows fof cartridges, so that the group of car- -tridges is moved upwardly as a unit, and j ammingof said cartridges in the magazine is prevented. Y. The side walls of the magazine are' preferab-ly formed with inwardly projecting ribs 72 with which the cartridges engage, as shown in Figure 3.3, these ribs reducing the extent of contact of the cartridges with-the magazine walls and facilitating the upward movement ofthe cartridges under.. the action of the spring. The side edges of the platform or4 follower 69 may engage these ribs, or they may be notched to receive the ribs which then serve `to guide `the follower in its upward and downward movements.

The side walls of the magazine at the upper ends thereof are inclined ,or converge toward each other as indicated at 73, and the extremities of these walls yare curved as indicated at 74, to enable them to contact with and fit partially around the surface of a single cartridge 43. The centre of curvature of the extremities 74 lies in the longitudinal median plane of the magazine. Thus when the uppermost cartridge 43, Figure 12, is removed fromI the magazine by the bolt 25,

the next lower `cartridge 43 is pressed upp ment and removal by the bolt.

wall of the magazine into position between' Awardly into contact with the inclined or converging end 73 of the side w'all of the magazine and yis guided by said inclined end toward the longitudinal median plane of the magazine, and is finally pressed by the cartridge 432 beneath-,it into contact with the curved extremities 74 of the" side walls, being positioned by said walls for engage- When the cartridge 43 so positioned is removed by the bolt, the cartridge 432 is similarly pressed upwardly and guided by the ini clined or converglng end of the opposite side Athe extremities 74, the operation being repeated at each removal of a cartridge. Thus cartridges are positioned for engagement by Y the bolt, alternately from the two rows of cartridges in the magazine, and it will be l of the gun in operation.

:1,430,661lv l 'magazineinsteadiof the alternate feeding in the'feeding of the zines. This uniformityl ncreases the efficiency cartridges necessarilyl The cartridges might be guided into place between the extremities 74 by pressing the metal of the side walls inwardly, a greater distance at the upper ends ofthe ribs 72, to

form inclined or converging ribs, from a point below the inclined ends 73 to said extremities 74, these 'converging ribs then guiding the cartridges into place. These inclined or converging ribs might be used with a magazine having plain sidewalls, or the 11p-per end of the magazine might be otherwise formed to ensure the cartridges' being guided alternately from the two rows thereof into the longitudinal median plane of the magazine. 1 v The forward portions of the side walls o f -the magazine converge toward each other,

as indicated in Figure 33, following substantially thecurvature of the bullets 75, theA y platform or follower 69 being correspondin ly shaped at its forward end'.

't will be noted from Figures 2, 31 yand i 32, that the curvedV extremities 74 of the side walls of the magazine extend substantially halfway from rear to front of the magazine and their extreme forward edges co-act with each cartridge during itsvmovement by the bolt, to hold its rear end or head in the magazine until the bullet 75 is guided by .the inclined surface 76 on the body, into the chambered end of the barrel.

The cartridge is then released from said extremities, and by themovement of the succeeding cartridge into place, is thrown upwardly slightly to bring it into substantial alignment vskiththe axis of the barrel.`

The spring 70 is preferably secured to the follower 69 by means of lugs or ears 77 bent over at the side edges of the follower, and between which lugs and the follower the upper leaf of the spring is inserted. These lugs may be formed on the follower by rolling or pressing down lthe forward side edges thereof, so as to shape the fortime form the lugs, between which and the follower the forward end of the upper leaf of the spring is inserted. The spring may be similarly secured ltothe bottom plate 78 although it may of course be secured to the ward end of the follower and at the same follower, or to the bottom plate, in anyv other convenient way.

The bottom plate 78 may be soldered or otherwise permanently securedy to the walls of the magazine, or said plate ymay be removably secured thereto by suitable catches on said plate or said walls, which are releasable by an operator equipped with a suitable tool, yto permit the follower and grooves in the walls of said recess,

are preferably slightly curved as indicated in Figures 2, 4 and 31, to allow for the curvature or inclination of the front and rear ends of the group of cartridges due to the slight tapering of the walls thereof. The upper edge of the rear wall is curved coincidentally with the wall of the bore 28, and the extremities 74 hohl the cartridges so that the heads thereof project just sufficiently above said curved edge to enable them to be engaged by the bolt. The cartridges are inserted in the magazine through the opening in the top thereof in the usual manner, and the magazine may be constructed to hold five` ten, fifteen, twenty or other suitable number as may be desired.

lThe magazine is inserted in a recess formed in the lower part of the body, in communication with the lower bore 28 therein, the forward wall of the magazine having an aperture adapted to engage over a pin 79 in the forward wall of` the recess, and the rea-r wall co-acting with a latch 8() which extends through an aperture in the wall 47 into a notch or aperture 81 in the said rear wall, which wall may be slightly pressed out above the notch, as indicated to more se'- curely co-act with the latch. y

The latch 80, as shown in Figures 2, 19 and 20, is mounted in a recess in the forward end of the guard 44 of the trigger mechanism, the latch having tongues 82 on its side faces co-acting with corresponding and being pressed forwardly by a spring 83. The

forward and rearward movements of the latch are limited by a pin 84 co-acting with a groove or recess 85 in the upper face o the latch. By rearward pressure against the rear curved end 86 of the latch, which is located in close proximity to the trigger 50, the forward end of the latch may be released from the notch 81, thus permitting the magazine to fall or be removed from the recess in the body. Thus without substantially changing the position of the hand in firing, an empty cartridge magazine may be released from the firearm and a loaded magazine substituted in place thereof by means of the other hand, enabling the reloading of the firearm to be effected with extreme rapidity and ease.

`When a cartridge is pressed into the chamberedy end of the barrel, its rear end or head as indicated in Figure 4, extends into a recess 87, inthe forward end of the bolt 25 and the extractors 88 which normally eX- tend inwardly into said recess snap over the rim of the cartridge head vin the usual way, so that the empty cartridge case is withdrawn from the end of the barrel when the bolt moves rearwardly. The improved construction and arran ement of the extractors 88 is indicated in 4`igures 27 to 30, and it will be noted that they are formed from a single piece of resilient metal, comprising a curved body portion 89 from which the two extractors 88 extend longitudinally, and which has a pair of laterally extending arms 90. The reduced forward end 39 of the bolt at or adjacent the junction thereof with the main portion of the bolt is cut away to form the tapering or inclined walls 91. The extractor member is laterally applied to the bolt by pressing the resilient arms 90 over the spaced edges 92 of the walls 91, the arms 90 then moving together to grip said walls, as indicated in Figure 29, and securely holding the extractor member in place on the bolt. The extractors 88 and body portion 89 preferably lie in recesses in the forward end 39 of the bolt so as to be fiush with the circumferential surface thereof. ly neat, simple and easily manufactured eX- tractor member and one which 4cali be readily applied and removed when necessary. x

During the rearward movement of the bolt, the empty cartridge case is ejected by the ejector mechanism illustrated in Figures. 10, 12 and 30. The ejector member 93 is centrally pivoted within a chamber or recess 94 at one Side of the body 3, this re` cess communicating with the bore 28 through apertures 95 and 96. The bolt 25 at its rear end is provided with a cam surface 97 which at a predetermined point in the return movement engages the rear end of the ejector member 93, which extends into the bore 28 through aperture 95, and presses the said end into the recess 94, forcing thelforward f end of said ejector member through aperture 96, into the bore 28 and into contact with the empty cartridge case held by the extractors 88. The cartridge case is thus ejected from the recess 87 in the end of th'eJ bolt through an ejection aperture or slot T his construction provides an eXtreme- A 98 formed in the wall of the'body 3, Figures 2 and 12. The chamber or recess 94 if closed by means of al cover plate 99 sliding in grooves in the outer edges of the recess walls, one end of the cover, which may be the front end as in Figure 1, or the rear end as inFigures 4 and 10, having a lateral lug or ear 100 which extends into a recess 101 in the body, whereby the cover may be removed by inserting the end of a bullet in said recess to engage the lug 100 and sliding the cover forwardly or rearwardly in its guiding grooves.

It will be noted that the ejector member 93 is arranged in a plane which is inclined from the horizontal plane passing through the axis of the bore 28 of the body, wherebythe amount of projection of the walls of the recess 94 from the body 3 is reduced .toa minimum, this adding to the neat appearance ofthe firearm, and reducing the danger of the gun being caught in or damaged by obstructions. The ejection aperture 98 is arranged in a plane inclined to the said horizontal plane and beneath the same so that the empty cartridge cases are thrown outwardly and downwardly and do not interfere with the operator either in operating or sighting the gun.

The butt stock 102 may of course be secured to the butt tang 34 in any usual or convenient manner, but it is preferably secured thereto by the means illustrated ,in Figures 1, 2, 6 and 8. That is, the stock is secured to the tang by means of a tube 103 which is screw threaded at its upper and lower ends. The upper end of the tube is threaded into thel interiorly screw-threaded lugs 104 projecting rearwardly and downwardly from the butt tang plate 33. The butt stock is 'bored to it over thel tube 103 and its upper end is shaped to fit within and be flush with the exterior surface of the rearwardly extending flange 105 of the butt tang. The butt-plate 106 is formed with a recessed portion 107 pressed outwardly therefrom, which fits within a recess in the rear end of the butt stock. The

, butt plate, stock and tang together.

rear end of the tube 103 extends into the recessed portion 107 and a nut 108 threaded onto the end of the tube and pressing against the wall of said portion securely holds the The nut 108 may be provided with ears 109 to which are hingedly connected cover pla-tes nected the rear sling swivel 113, such swivel thus being securely connected to the butt plate instead of by screws to the butt stock as usual. The assembledl butt stock and tang are removably connected to the body 3 iii the manner illustrated in Figures 2, 4, 7, 8 and 9. The tang is formed with a forwardly extending flange 114 the forward4 edge of which has an inwardly extending fiange 115', the flange 114 corresponding in shape to the rearend of thebody, as will be seen from Figures 7 and 9, and its lower portion being open or cut awayl as shown in Figure 7. The rear end of the body 3 isl provided with an outwardly `extending flange 116. The tang mayV thus be slid downwardly over .the end of the bodyl portion, with the said end in contact with the butt tang plate 33, and the flange 114 will when the -tang is in place, prevent downward and lateral movement thereof, andthe plate 33 and the co-acting flanges 115, 116 will prevent relative longitudinal movement between the tang and body. To prevent the tang being removed upwardly from the body except when it is desired to disconnect the stock and tang from the body, the plate 33 is provided at its lower part with a notch or aperture 117 with which the nose 118 of a pivotal latch 119 is adapted to engage. This latch is pivoted on a pin 120 within a recess 121 in the rear end of the guard .44 of the trigger mechanism, this `latch when in the position indicated in Figure 4 permitting the butt tang to be applied and removed, and when in the position indicated in Figure 2 preventingremoval of the tang by engagement of its nose 118 with the lower wall of the notch v117. The forward portion of the latch is bifurcated at 122, see Figures 19 and 20,'and the arms of the bifurcation are normally slightly spread apart, so that when in the position of Figure 2, they resiliently engage the walls of the recess in the guard with suflic-ie'nt pressure to hold the latch in locking position.

123 and the guard adjacent said aperture has recesses 124, so that by insertion of the j pointed end of a bullet in one of the recesses and in the aperture 123 the latchmay be readily released to permit the butt tang and stock to be removed from the body.

The firearm may be provided with rear and front sights constructed and arranged on the arm in any usual manner known in the art. It is, however, preferred to arrange these sights in the manner shown in Figures The head of the sight is formed with a peep y or other sighting aperture or notch 127, and the body of the sight is bifurcated to pro- .vide two arms 128. These arms are slightly sprung away from each other, so that when inplace in the slot 125 the side edges of the sight are resiliently pressed into contact with the edges of the slot to hold orA assist in holding the sight in any position to which it may be vertically adjusted within said The forward end of the latch is provided with an apertureV slot. The edges of the sight and of the slot may .be roughened, if desired, to assist in holding the sight'in adjusted position. The

sight is provided with suitable range graduations lco-operating with zero marks formed on projections 129 at the upper part of the tang.

It may in some or all cases, bedesirable to provide other means for holding the sight in its adjusted positions, and such means may comprise the pin or bar 130 slidably mounted in bearings 131 in the butt tang transversely of the sight. This pin is provided with a recessed or cut-away portion to enable it to fit over the sight as in Figures 2 and 8, and to provide a shoulder 132 adapted to co-act with one of the side edges of the sight. The pin is normally pressed outwardly by means of a spring 133 of sufficient strength to hold the face of the shoulder 132 against the edge of the sight with sulicient pressure to prevent movement of the sight from its adjusted positions. The face of the shoulder 132 may be roughened if desired. `The pin 130 is provided with a headi134, and it will be understood that by pressure of the thumb or other part against this head, the face of the shoulder may be moved away from the edge of the sight to permit vertical adjustment of the latter in accordance with the range desired, as indicated'by the range graduations cooperating with the zero marks, and that when the pressure on the head is relieved, the spring will again force the face of the shoulder against the edge of the sight to hold the same firmly in its adjusted position. There is thus provided an extremely simple construction of rear sight which may be quickly and easily adjusted to the desired range and which may be readily replaced in case of damage or breakage. In its innermost position, the upper part of the sight is practically flush with the upper part of the tang and the danger of breakage of the sight or of catching the same in obstructions is reduced to a minimum.

The front sight 135 is mounted upon a split clip or band 136 which as will be clear from Figures 5, 15 and 16, is shaped to fit the con centric and enlarged portions of the casing4 and to abut againstthe shoulder 16 hereinbefore described. The clip is adapted to be passed rearwardly along the concentric portion 14 of the casing 4 and to be firmly secured in place thereon against shoulder 16 by means of the screw 137 passing through an aperture in one of a pair of ears 138, depending from the lower portions of the clip, and threaded into the other of said ears, Figure 16. r1`he screw 137 also forms a pivot for the stacking swivel 139 located between said ears 138, and when tightened no: only serves to clamp the halves of the clip firmly against the surface of the casing, but also to grip the swivel 139 between the ears for a purpose later referred to. A second air of ears 140 depend from the lower portions of the clip 136 and between these is pivoted the front sling swivel 141 this swivel preferably being formed with pivots 142, Figure 15. held within the apertures in the ears by the resiliency of the clip and the tightening of the screw 137.

1n light machine guns such as illustrated swivel.

in the drawings, it is usual to provide a firing mount or restfor the gun so that the same while being fired may be supported from the ground or other object if desired. It may also be desirable to provide a guard or shield to protect the machine gunner from being struck by enemy bullets, shell splinters or the like. In Figures 5, 15 and 16, is illustrated a metallic member or plate 143 which may serve not only as a firing mount or support for the gun by resting the lower part thereof against the ground or other object, but which also serves as a shield or protector for the head or body of the gunner when firing the gun. 1t will also be clear that the mount or shield 143 serves as a body protector for the gunner when advancing .with the gun held substantially horizontally in the usual manner. as the shield will thus be held infront of the gunners body and will afford some measure of protection thereto. The shield is preferably of convex or dished form as illustrated in Figure 5 so that bullets on striking the same may glance obliquely from the surface thereof.

The mount or shield is mounted upon the clip or band 136, havinga central aperture 144 which fits the concentric portion 145 0f said clip. and other apertures 146. 147 eX- tending from the central aperture, o f which the former is of. such shape as to pass over the stacking -swivel 139 and the latter is in the form of a slot adapted to co-operate with the projection 148 at the upper end of the The mount or shield is positioned on the clip 136 by passing it along the casing 4, (with the aperture 146 beneath the casing so that it will pass over the swivel 139, when the latter is in the dotted line position indicated. in Figure 5) until the mount abuts against the shoulder l149 on the clip and against the ears 140. The mount is then turned to bring the aperture 146 into the upper position indicated in the figures, and the slot 147 into, line with the stacking swivel, and the latter is then rotated into the position indicated in full lines in Figure 5, so that its projection 148 will extend into the slot 147 and prevent movement of the shield. The gripping of the swivel 139 between the ears 138, as previously mentioned, holds the swivel with sufficient pressure to prevent accidental movement of the same to release the mount. The edges of the slot 147, it will be noted, are positioned between the two pairs of ears 138 and 140, and the mount is thus held firmly in place on the clip. The aperture 146, as will be seen from Figure 15, provides a field of vvision surrounding the front sight 135, so hat the gun may be properly sighted.- The mount or shield 143 may, of course, be secured on the gun by other means than thos illustrated and described.

It is desirable to cover the rear enlarged portion of the casing 4 with a heat-insulating covering 150, which as illustrated in Figure 14, is shaped to fit the said portion of the casing. This covering which may be of wood or other suitable material, is held in place between the band 5, securing the casing to the body, and the front sight band y 136,- as shown in `Figures 1, 2 and 5.

It will be understood from the previous description that the guard 44 of' the trigger mechanism is held in place by the tang 34 when the latter and the butt stock are positioned on the body, and that said guard is provided at its rear and front ends with means for holding in place the tang and butt stock, and the cartridge magazines. The lowermost edges 151 of the body 3 preferably extend downwardly a sufficient distance to cover the pins 51. 84 and 120, of the trigger mechanism. so as to conceal these pins and at the same time to prevent accidental displacement thereof'` the pins heilig simply pressed into place and held there by the said edges. The edges 151 are notched at 152 to receive the end of the handle 63.

The front wall 18 of the casing 4 may be formed in the manner indicatedin Figures 1 and 5, so as to provide a means by which on the tapering forward end 17 'of said caston 19 when at or near the rear end of its stroke does not touch the wall of the casing at the enlarged portion 4a. A clear passage for air is then provided inside the casing from the inletI ports 40a to the mouth.

' The discharge gases issuing from the mouth 5c of the casing induce a powerful draught, thus effecting a circulation of air between the casing and the gun barrel and effectively.

coolingthe latter. If desired, the rod 23 may loosely fit Within the forward portion of the body, so that the piston 19 may circulate cooling air over the actuating mechanism of the firearm andrwithin the body 3, for the purpose of maintaining said parts and body, in addition to the barrel, in cool conditionduring operation of the firearm. Or the gases of discharge may be otherwise utilized to produce said circulation of cooli air. f

`xht will be readil lunderstood that the a bayonet may if desired be readily secured cartridge or powdercharge, as distinctv from a firearm operated by the application of the pressure of the gases of discharge against a par-t connected to the actuation mechanism. The invention is not restricted to any particular form of means for producing these shocks or impulses, although vvarious means for this purpose have been described in order 'that the invention may be clearly understood. Furthermore/the invention is not restricted to any particular construction or size or calibre .of firearm, as although the principles of the invention may be particularly applicable to rifles or' shoulder arms, and for convenience a irey armV of this character has been described lin detail, the invention is also applicable, as

will be clearly-understood by4 those skilled in the art, to firearms of other types or lconstruction and of smaller and larger size or calibre.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. An automatic firearm, comprising in combination, a body portion, a barrel carried thereby, actuating mechanism located within said body portion, means acting upon the discharge gases to produce -ashock or very rapid pressure impulse, and means for transmitting the energy of said shock or impulse to said actuating mechanism to energize the same. (i

2. An automatic firearmacomprising in combination, a body portion, a barrel carried thereby, actuating mechanism located within said body portion, vmeans extending in advance ofthe muzzle end of said barrel and acting upon the discharge gases to produce a` s ock or very rapid pressure impulse, and means for transmitting the energy of said shock or impulse to said actuating mechanism to energize the same. I 3. An automatic firearm, comprising in combination, abody portion, a barrel carried thereby, actuating mechanism located within said body portion, means' located in advance of the muzzle end of said barrel and co-acting with the discharge gases to y ried thereby,

Y gases discharge gases momentarily check the forward movement thereof to produce a shock or very rapidv pressure impulse, and means for transmitting the energy of said shock or impulse to said actuating mechanism to energize the same.

4. An automatic firearm, comprising in combination, a body portion, a barrel carried thereby, actuating mechanism located within said body portion, means surrounding the muzzle end of said barrel and'extending in advance thereof to momentarily check the free expansion of the discharge to produce a shock or very rapid pressure impulse, and means for transmitting the energy of said shock or impulse to said actuatingV mechanism to energize the same.

5. An automatic firearm, comprising in combination, a body portion, a barrel carried thereby, actuating mechanism located within said body portion, a casing having a portion extending in advance of the muzzle end of said barrel to form a chamber in communication with the atmosphere at its forward end, said portion being constructed to act upon the forwardly moving to impose a shock or wave of compression upon the body of air within said casing, and means within the casing for transmitting the energy of said shock to said actuating mechanism to energize the same.

6. An automatic firearm, comprising in combination, `a body portion, a barrel carried thereby, actuating mechanism located Within said body portion, a casing having a portion extending in advance of the muzzle end of said barrel to form a chamber in communication with the atmosphere at its forward end, a piston slidable within said casing at a materialdistance to the rear of its forward portion, said portion being constructed to act upon the forwardly moving discharge gases to impose a shock or wave of compression upon the body of air in advance of said piston, and a connection between said piston and said actuating means for energizing the latter.

7. An automatic firearm, comprising in combination, a body portion, a barrel caractuating mechanism located within said body portion, a casing surrounding said barrel and having a portion extending in advance of the muzzle end thereof to form a chamber in communication with the atmosphere at its forward end, an annular piston slidable upon said barrel and fitting within said casing an having its forward end at a material distance to the rear of the muzzle end of the barrel, said casing portion being constructed to act upon the forwardly moving gases to impose a shock or wave of compression `within said body portion,

upon the annular column of air in advance of said piston, and a connection between said piston and said actuating means for energizing the latter.

8. An automatic firearm, comprising in combination; a body portion, a barrel carried thereby, actuatin mechanism located within said body portion, means located in the path of movement of the discharge gases apertured to permit the passage of a bullet and adapted during such passage to momentarily confine and check the forward movement of said gases to produce a shock or very rapid pressure impulse, and means for Vtransmitting the energy of said shock to said actuating mechanism to energize the same.

combination, a body portion, a barrel carried thereby, actuating mechanism located and means concentrically disposed about the axis of the gun barrel in advance of the muzzle end thereof to momentarily and uniformly check and confine the discharge gases to produce a shock or rapid pressure impulse without causing lateral deflection of said gases, for the purposes set forth.

comprising in l0. An automatic firearm, combination, a body, portion, a barrel carried thereby, actuating mechanism located Within said body portion, means confining a body of elastic fluid, means operative upon the discharge gases. to' impress a shock or wave of compression upon said body of transmitting the energy of said impressed shock to the actuating mechanism to energize the same.

11. An automatic firearm, comprising in combination, a body portion, a barrel carried thereby,

actuating mechanism located within saidv body portion, a casing carried by said body portion and surrounding said barrel, said casing having its forward portion concentric with the barrel and extending beyond the same and being enlarged at its rear portion, air inlets in said enlarged rear portion of the casing, means at the forward endvof said casing operative upon the discharge gases to produce a shock of compression and rarefaction, and means positioned within the concentric portion of the casing to receive said shock and movable thereby into the enlarged portion of the casing to permit the forward flow of cooling air through said inlets.

1Q. An automatic firearm, comprising in combination, a body portion, a barrel carried thereby, actuating mechanism located within said body portion, a casing surrounding said barrel and confining 'a column of air, means at the forwardz end of said casing operative upon thedischarge gases'to impress a shock or wave of compression 9. An automatic firearm, comprising in upon said body of fluid and a pistonwithin said casing to receive the impressed shock and transmit the same to the actuating mechanism to energize the same.

13. An automatic rearm, comprising in combination, a body portion, a barrel carried thereby, actuating mechanism within said body portion, meansimmovably arranged at the muzzle end of said barrel and acting on the discharge gases to produce a shock or compression wave, and movable means receiving said shock or wave and transmitting the same to said actuating mechanism to energize the same.

14. An automatic firearm, comprising in combination, a body portion, a barrel carried thereby, actuating mechanism within said body portion,Vv means immovably arranged at the muzzle end of said barrel to momentarily check the forward movement of the discharge gases to produce a shock or compression wave, and movable means receiv ing said shock or wave and transmitting the same to said actuating mechanism to energize the same.

15. An automatic firearm, comprising in combination, a 4body portion, a barrel carried thereby, actuating mechanism within said body portion, means immovably' arranged at the muzzle end of said barrel to momentarily check the expansion of the discharge gases to produce a shock or compression Wave, and movable means receiving said vshock or wave and transmitting the same to said actuating mechanism to energize the same.

16. An automatic firearm, comprising in combination, a body portion, abarrelcarried thereby, actuating mechanism within said body portion, immovable lmeans surroiuiding the muzzle end of said barrel and eX- tending forwardly therefrom and acting on the discharge gases to produce a shock or compression wave, and movable means receiving said shock or wave and transmitting the same to saidV actuating mechanism to energize the same.

17. An automaticpfirearm, comprising in combination, a body portion, a barrel carried thereby, actuating mechanism within 'said body portion, a casing surrounding said barrel, and extending in advance of the muzzle end thereof and fixedly connected tov said body portion, said casing having a forward portion constructed to act on the discharge gases to produce a shock or compression wave, and movable means within said casing' receiving said shock or Wave and transmitting the same to the actuating mechanism produce a shock or compression wave, /agndfig movable means within said casing receiving said shock or wave and transmitting the same to Vthe actuating mechanism toV energize 'the same. 19.'An automatic firearm, comprising in combination, a body portion, a barrel carried thereby, actuating means within said body portion, means immovably located in the path of the discharge gases apertured to permit the passage of a bullet and acting on the discharge gases to momentarily confine the same to produce a shock or compression wave, and movable means receiving said shock or wave and transmitting the same to said actuating mechanism to energize the same.

20. An automatic firearm, comprising in combination, a body portion, a barrel carried thereby, actuating mechanism within said body portion, acasing immovably surrounding said barre] throughout the length thereof and extending in advance of the muzzle 4end' of the same, and movable means within said casing spaced from the muzzle end of the barrel to provide a column of a1r 1n advance of said means, said casing at the forward portion thereof being constructed to act on the discharge gases to impose a shock or compression Wave upon said movable means through said column of air.

21. An vautomatic firearm, comprising lin combination, a body portion, a barrel carried thereby, actuating mechanism within said body portion, a chamber immovably located in advance of the muzzle end of said barrel to receive the discharge gases issuing therefrom and co-operating with the discharged bullet to momentarily `confine and enclose said discharge gases to produce a shock or compression wave, and movable means associated with said chamber to receive said shock or wave and transmit the same to the actuating mechanism to energize the same.

VIsaac N. LEWIS. 

